Solving Systems with an Inverse Matrix
Algebra
Level
2
A system of equations is given by
\[\begin{align} ax + by &= 5 \\ cx + dy &= -1. \end{align} \]
If the inverse of \(\left[ \begin{array}{cc} a & b \\ c & d \end{array} \right]\) is \(\left[ \begin{array}{cc} 3 & 2 \\ -3 & 1 \end{array} \right]\), then what is \(x + y?\)
by
Andrew Ellinor